1. Field of the Invention
The present invention relates, in general, to a golf ball having indications for guiding a golfer to sight a direction to hit the golf ball (hereinafter referred to as xe2x80x9cdirection-sighting indicationsxe2x80x9d) and a mold for manufacturing the same and, more particularly, to a golf ball having direction-sighting indications, with which a golfer can easily sight a desired direction for the golf ball to travel when he/she strikes the ball with one of golf clubs, and a mold for manufacturing such golf balls.
2. Description of the Prior Art
As well known to those skilled in the art, to make any shot in a golf game, a golfer initially determines a target point of a golf ball to hit the ball, adjusts his/her stance, knees, waist and shoulders so as to be parallel with the desired flight path of the ball, and then places the head of a golf club directly behind the golf ball so that the club head is aligned perpendicular to the desired flight path, which is a correct posture for a golf swing.
However, since the golfer is dependent upon eye-measurement to determine a target point of the golf ball, the actual flight path of the ball may be easily diverged from the desired flight path and the actual flight distance of the ball may be easily different from a desired flight distance.
In order to solve this problem, there has been provided a golf ball with marked lines formed through an additional process to mark the lines crosswisely on the outer surface of a golf ball, wherein the marked lines have been used as direction-sighting indications.
Referring to FIG. 1, the direction-sighting indications are produced by forming an X-axial line and an Y-axial line on the outer surface of a golf ball 100, wherein the X-axial line is parallel with a straight line xe2x80x9cSxe2x80x9d which passes along a golfer""s stance for the correct swing, and the Y-axial line is parallel with a straight line 102 which passes along a hit face of a club head 101 to be perpendicular to the X-axial line. Therefore, the golfer is allowed to hit the golf ball 100 while placing the central point 103 of the hit face of the club head 101 such that the central point 103 is precisely aligned with the X-axial line. With the use of the indicating lines for sighting the direction, the golfer is able to hit the golf ball 100 so that it flies in a correct target direction to reach a desired distance.
The marked lines used as direction-sighting indications according to a conventional art have been printed on the outer surface of a golf ball. As well known to those skilled in the art, the outer surface of a golf ball is formed with hundreds of dimples (slight depressions or indentations formed on the outer surface) and thus it is not easy to mark lines on the outer surface of the golf ball so as to divide the outer surface into equal parts. If the marked lines are inclined to any side to be eccentric from the center of the golf ball, the golfer is unable to hit the golf ball in the target direction as desired. Further, it is not easy to correctly position a golf ball based on the marked lines, on the golf course. In addition, since the line-marking has been performed directly on golf balls through an additional process, about 60% to 70% of produced golf balls have been discarded in the course of marking the lines on the surfaces of the golf balls because correct line-marking has not been performed, which has caused the golf ball manufacturers a large amount of damages. Accordingly, there has been a heavy increase in production costs and a serious degradation in productivity of golf balls. Also, since the line-markings on the surfaces of golf balls are made with colors on the white surfaces of the golf balls for visibility, the surfaces of the golf balls on which trademarks and other normal signs, etc, are normally printed, seem distracting and disordered; this has not allowed the golfer to concentrate on a golf game, thereby causing the golfer to make an incorrect shot, contrary to the original propose of marking the lines on the surfaces of the golf balls. Since the golf balls with marked lines have caused errors in golf swings, a high percentage of incorrectly marked lines, poor productivity, bad visibility, impaired concentration, and low competitive power, the golf balls, the surfaces of which are formed with marked lines, have not been commercially successful although they are very effective in theory.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a golf ball having direction-sighting indications, wherein a plurality of indicating holes (a kind of dimple), clearly distinguishable from the normal dimples in shape and dimension, are formed along equators on the outer surface of the golf ball during a process of forming the normal dimples on the golf ball, thereby producing indicating lines on two to six crossing points, whereby the golfer is allowed to conveniently sight a target direction to hit the golf ball.
Another object of the present invention is to provide a mold for manufacturing such golf balls.
In order to accomplish the above objects, the present invention provides a golf ball having direction-sighting indications, including a first indicating line having a plurality of indicating holes distinguishable in shape and dimension from dimples formed on an outer surface of the golf ball, the first indicating line establishing a straight line extending along an equator on the surface of the golf ball to form a first direction indicating line, on which a starting point and an ending point are identical, and a second indicating line having a plurality of indicating holes identical in shape and dimension to those of the first indicating line, and establishing a second direction indicating line so that two crossing points with the first indicating line are formed and, at the same time, a first axis is formed through the two crossing points and a center of the golf ball.
The golf ball further includes a third indicating line having a plurality of indicating holes identical in shape and dimension to the indicating holes of the first and second indicating lines, and establishing a third direction indicating line so that one pair of crossing points is respectively formed with each of the first and the second indicating lines, and a second axis and a third axis are respectively formed through the two pairs of crossing points and the center of the golf ball.
In the golf ball, the first, the second and the third indicating lines may be preferably formed on the outer surface of the golf ball such that two or more first, second and third indicating lines are formed on the surface of the golf ball at equal angular intervals, with the first, the second and the third axes being respectively set as mutual axes of the two or more first, second and third indicating lines.
According to another embodiment of the present invention, the above objects can also be made by providing a mold for manufacturing a golf ball having direction-sighting indications, comprising at least one cavity, with a plurality of indication-forming projections being formed along an inner surface of the cavity to form a plurality of indicating hole on an outer surface of the golf ball so as to form at least two of the first, second and third indicating lines on the outer surface of the golf ball.